Membrane fission by dynamin: what we know and what we need to know - PubMed (original) (raw)

Both reaction pathways are populated by chemical intermediates defined in the figure. High energy states are indicated with an asterisk. Arrows indicate the reactions between each pair of intermediates. The sizes of the blue arrows are proportional to the rates under physiological conditions (taking into account the concentrations for bimolecular reactions) as defined at the bottom right. The black arrows in (B) indicate unknown rates. The bottom rows in (A) and (B) are reactions of myosin (M) and dynamin (G) monomers. The top rows are reactions of myosin bound to an actin filament (

AM

) or dynamin dimers (

GG

). The vertical arrows indicate the rates of myosin binding actin filaments and dynamin forming dimers. In (A), the right panel represents a superposition of myosin in the nucleotide‐free, pre‐power stroke state (pdb 2mys, white) and the

ADP

‐AlF4−‐bound rigor state (pdb 1br1, red).

ADP

‐AlF4− is shown in magenta, and the two myosin light chains bound to the lever arm are shown in blue and dark blue. The positions of the second light chain and the distal end of the lever in pdb 1br1 were modeled based on pdb 2mys. Five actin molecules (yellow) are indicated (from pdb 5jlh). In (B), the right panel represents a superposition of the G domains in the dynamin

GG

construct in the

GMPPCP

‐bound open (pdb 3zyk in red) and the

GDP

‐AlF4−‐bound closed form (pdb 2x2e in white). Nucleotides are shown in magenta. Note the 70° rotation of the

BSE

relative to the G domain.